Charging Time Required

The time required to charge a battery will vary depending upon the following factors:
- The size of the battery - A completely discharged, large, heavy-duty battery requires more than twice the recharging time as a completely discharged, smaller battery.
- The temperature - A longer time is needed to charge any battery at -18 °C (0 °F) than at 27 °C (80 °F). When a fast charger is connected to a cold battery, the current accepted by the battery is very low at first. Then, as the battery warms, the battery accepts a higher rate of current.
- The charging capacity - A charger which can supply only five amperes requires a much longer charging period than a charger that can supply 30 amperes or more.
- The state-of-charge - A completely discharged battery requires more than twice as much charge time as a half charged battery. Because the electrolyte is nearly pure water and a poor conductor in a completely discharged battery, the battery accepts very low current at first. Later, as the charging current causes the electrolyte acid content to increase, the charging current also increases.